


Disassembly

by JohnAmendAll



Category: Doctor Who (1963), Girl Genius
Genre: Clever Women, Gen
Language: English
Status: Completed
Published: 2016-07-19
Updated: 2016-07-19
Packaged: 2018-07-25 12:25:37
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,051
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/7532683
Author URL: https://archiveofourown.org/users/JohnAmendAll/pseuds/JohnAmendAll
Summary: <blockquote class="userstuff">
              <p>It isn't enough just to get past a hostile clank. Some people won't be satisfied until they know how it works.</p>
            </blockquote>





	Disassembly

**Author's Note:**

> Written for a crossover conversations meme: _Give me two characters from different fandoms you know I'm familiar with, and I'll give you a dialogue happening between the two of them. Without justifying how the crossover would work, how their worlds clashed or how they could even meet each other. Just a silly crossover conversation with no backstory, for fun._
> 
> [DabhidC](http://archiveofourown.org/users/daibhidc) prompted for Zoë meeting Agatha Heterodyne.

The two intruders kept their eyes on the foot-high silver swan. To the accompaniment of delicate music, the bird swung its head this way and that, dipped its neck to pluck something from the liquid in which it appeared to be floating, then raised its head— 

"Down!" Agatha shouted, pulling Zoë to the ground. Something tiny, sharp and silver whizzed over their heads and embedded itself in the wall behind them. 

"Eleven seconds," Zoë said, as they got to their feet. "It should be possible to get past it if we time our moves correctly." 

"Get past it?" Agatha gestured at the weapon hanging at her belt. "If I just wanted to get past it I could have melted it from back there. I want it _intact!_ " 

"Why do you—" 

"Dodge!" They jumped to either side as a silver shard lodged itself in the flagstones between them. Agatha pulled it clear with one gloved hand; it was a fish, exquisitely detailed, its edges razor-sharp. 

"Look at the craftsmanship of this," she said. "That swan was made by one of the greats. Maybe even Van Rijn. Destroying it would be a crime. I want to _study_ it." 

"Oh, of course!" Zoë dived to the floor again as the swan spat another of its lethal missiles. "But can you shut it down safely?" 

"If you keep it distracted." Agatha ducked around the swan's pedestal and pulled a telescopic rod out of her backpack. Moving carefully, she rose to her knees and began to probe the silvery, roiling liquid surrounding the swan. Zoë, doggedly counting under her breath, dodged this way and that under the swan's continued fire. 

"It's speeding up!" Zoë called, as a lethal silver fish whipped past her shoulder. "That one was only eight seconds!" 

"Almost there..." Agatha gave the rod a twist. "Got it!" The swan's head came to a graceful halt, the glow in its eyes fading. The liquid subsided into flat silvery calm. "It's safe now." 

"So who was this Van Rijn?" Zoë asked, joining her beside the swan. 

"You haven't heard of him?" 

Zoë searched her memory. "I remember being taught about a painter by that name." 

"Oh, he was far more than a painter. He was the greatest Spark of his age. Some of his creations still haven't been matched today." Agatha cautiously touched the swan's back; blue sparks crackled over her glove. 

"But surely they could be reverse-engineered. No machine's design can be kept secret if the machine itself can be studied sufficiently closely." 

"It isn't as easy as it sounds. Van Rijn's creations are delicate: tamper with one in the wrong way and you'd just destroy it." 

"Well, can't you start with a noninvasive scan? A gamma-ray imager... oh. Those probably haven't been invented yet, have they?" 

Agatha shook her head. "Describe one." 

"I'm not sure that would help." 

" _Describe one._ " 

"Well, you put a constricted gamma ray source on one side of the object and a detector on the other, and by rotating it through three hundred and sixty degrees you get an idea of the cross-section. And then you repeat, building up images as you go." 

Agatha was gazing thoughtfully into the middle distance. "Those N-Ray goggles Martellus had. If I integrate them with a high-pass filter at the collimation stage..." 

She searched her backpack and pulled out a pair of brass-rimmed goggles. Whistling a complicated tune, she partially dismantled the goggles, then began to dig components out of her pockets. One by one, they were tacked onto the goggles, then secured in place with the aid of tools she pulled from her belt. Absorbed in her work, she resembled a gardener tending an elaborate piece of topiary, or a sculptor shaping clay. 

Presently, she returned the tools to her belt, held the goggles up before her face, then directed them at the swan. 

"Want to take a look?" she asked. 

Zoë eagerly took the goggles, and looked through them at the swan. The silvery outline of the bird was overlaid with gears, rods, chains and cams, layer upon layer, drifting this way and that at the slightest movement of her head. 

"Have you got anything to write with?" she asked. She leaned closer, enough to make out the teeth on each cog. "It looks like the basal logic's part quinary and part octal. Is that supposed to make it harder to reverse-engineer, or was the designer just crazy?" 

"It was built by a Spark," Agatha said simply. 

"I see." Zoë tilted her head, letting the layers of clockwork blur and reform. "So _that_ 's the sensory feed, and _that_ 's the targeting logic, so the main state machine must be on _this_ layer. Can you turn it on? I want to see it go through the states." 

Agatha produced her telescopic rod once more, and reached for the hidden switch. "Turning on in three. Two. One. Now!" 

The swan clicked into life. 

"Yes, I see," Zoë said. "Idle... Tracking... targeting... locked on... Firi—" 

Agatha pulled her aside; a razor-edged fish shot through exactly where her head had been. 

"And back to Idle," Zoë said, seemingly unaware of anything outside her mental image of the swan's mechanical brain. "But those are only five states, and that camshaft has at least seven. It ought to be possible to get it into the other two. It's got to be some combination of the sensory inputs — but I _bet_ if I can get the fire control logic to go out of range I can find out just what those extra states do!" 

"That's simple enough." Agatha was already assembling another impossible collection of components. "How many targets do you think the swan can track in one go?" 

"Thirteen." 

"Then fourteen Wurlitz Ghosts should do it." Agatha paused briefly as a thought struck her. "Or we could just turn the swan off again and come back to it later." 

Zoë pushed the goggles up on her forehead. "I'm not going to be beaten by some stupid clockwork bird. You can go on if you don't want to hang around waiting for me." 

"No, I'll stay here." Agatha was finding the expression on the other girl's face all too familiar. _I'm going to make sure I keep you right where I can see you,_ she silently added.

**Author's Note:**

> You can see our Universe's version of the swan at the [Bowes Museum](http://www.thebowesmuseum.org.uk/Collections/ExploreTheCollection/TheSilverSwan.aspx).


End file.
